1. Field of the Invention
The present invention relates to a spraying head assembly, and more particularly to a spraying head assembly that reduces liquid nebulization and raises a liquid ejection distance.
2. Description of Related Art
With reference to FIGS. 6 and 7, a conventional spraying head is used to spray liquids and comprises a body (60), a cap (61), a pressing tab (611), an upper plug (62), a lower plug (64) and a spring (63). The body (60) is tubular and has a spraying end, a connecting end, a chamber (601) and a connecting channel (602). The connecting end of the body (60) is connected to a pipe using threads. The chamber (601) and the connecting channel (602) are defined respectively in the spraying end and connecting ends of the body (60) and communicate with each other to define a shoulder between the chamber (601) and the connecting channel (602).
The cap (61) is attached to the spraying end and has a through hole defined through the cap (61).
The pressing tab (611) is squeezed between the spraying end of the body (60) and the cap (61) and corresponds to and closes the through hole in the cap (61). The pressing tab (611) has a hollow protrusion, a spraying hole (612) defined through the center of the hollow protrusion and multiple spraying channels (613) and a bottom. The spraying channels (613) are formed tangentially from the hollow protrusion in the bottom of the pressing tab (611).
The upper plug (62) is held in the chamber (601) of the body (60) and abuts the pressing tab (611). The upper plug (62) is smaller than the chamber (601) so defines a gap between the upper plug (62) and the inner surface of the chamber (601), which communicates with the spraying channels (613) in the pressing tab (611).
The lower plug (64) is mounted moveably in the chamber (601) of the body (60) and abuts the shoulder in the body (60).
The spring (63) is connected between the upper and lower plugs (62,64) to push the lower plug (64) to prevent the chamber (601) communicating with the connecting channel (602).
When the liquid is forced into the body (60) through the connecting channel (602) from a pipe, the lower plug (64) is dislodged to allow the liquid to enter the chamber (601). The liquid flow from the chamber (601), through the spraying channels (613) and hollow protrusion in the pressing tab (611) and ejected from the spraying hole (612) in the pressing tab (611) in a jet. With the arrangement of the spraying channels (613), a vortex will occur inside the hollow protrusion such that the liquid sprayed out from the spraying hole is nebulized.
However, only one vortex occurs before the liquid is ejected from the conventional spraying head, so particles of the jet are large and only travel a short distance. Therefore, a spraying range of the conventional spraying head is limited.
To overcome the shortcomings, the present invention tends to provide a spraying head assembly to mitigate or obviate the aforementioned problems.